Tips for helping with emotional regulation.... daycare is struggling with our son

My son just turned 3 years old and some days are great, but other times he has these 20-30 min meltdowns over nothing really....like asking to put shoes on or going outside with his class. He gets into this spiral of crying like it's literally the end of the world and it's so hard to get him to snap out of it. Daycare is struggling because he distracts the group and while there are 3 teachers they cannot always sit and reason with him multiple times a day. I am worried he might get kicked out. Another thing that might be related is he will ask 20 times in a row for something no matter how many times I tell him I heard and will get it. My husband has diagnosed ADHD and so does his brothers, not that I am totally jumping to that conclusion, but if there are behavioral things tailored to that it could help

Next week he has his 3 year appointment and I was wondering about getting a referral or something. What would I even be looking for? OT or a behaviorist? Should I be stricter with him and shit down the crying right away? Another option is moving him to a preschool that has only 3 year old. Right now he is around kids 1-6 years and it's such a big range. I am open to suggestions!